Open Process Control (OPC) is a software interface standard that allows WINDOWS programs to communicate between OPC enabled servers that have implemented an OPC server client. One area that OPC enabled servers are used is in industrial hardware devices used in manufacturing plants and refineries. The acronym OPC comes from OLE (Object Linking and Embedding for Process Control). OLE is partially based on the WINDOWS component object model (COM) standard and OPC shares some common features with COM. OPC is implemented over a client/server network.
The OPC server contains a software program that converts the hardware communication protocols used by industrial hardware devices such as programmable logic controllers (PLC) into the OPC protocol. The OPC client software includes programs to connect to the industrial hardware devices such as a human-machine interface. The OPC client uses the OPC server to receive data and/or transmit commands to the industrial hardware devices. Each OPC enabled computer can have hundreds of server connections. Unfortunately, with large numbers of server connections, a problem or duplication in one or more server connections can cause problems such as a loss of data and receipt or transmission of incorrect data.